Piston for an internal combustion motor



Feb. 16, 1937. E. c. LONG 2,071,131

PISTON FOR AN INTERNAL COMBUSTION MOTOR Filed Sept. 9, 1932 i I- Q A \v \w [r2 z/ezzfan' Patented Feb. 16, 1937 V #UNITED STATES PATENT OFFICE MOTOR PISTON non AN INTERNAL. COMBUSTION Elmer 0. Long, Grosse Pointe Park, Mich. Application September 9, 1932, Serial No. 33,325 Claims. (01. 309-11) This invention relates to pistons for internal combustion motors and has for its primary-object to provide'a piston with an improved flexible skirt which is capable of adapting itself to a 5' snug and proper guiding fit for the piston iii an I intemalcombustion motor cylinder, during contraction and expansion of the piston, attendant,

with thermal conditions.

Another object of the invention is in' providing a piston with a flexible skirt which is free from being supported by the pin bosses. I A further object of the invention is in providing a piston with a skirt which is slotted in an imgo Still another object of the invention is in pro accompanying drawing, exemplifying the invention, and in which: Figure 1 is an elevation of one of the pin boss sides of this improved piston.

- Figure 2 is a longitudinal vertical section taken approximately on the line lIII of Fig. 3.

Figure 3 is a longitudinal vertical section taken approximately on the line III-III of Fig. 2.

Figure 4 is a horizontal section taken approximately on the line IV -IV.of Fig. 2.

Referring by numerals to the accompanying drawing i designates the headof the piston havingan annular depending side wall 2 and packing ring grooves 3 in the side wall and depending from the side wall 2 in opposite disposition are a pair of legs 4 which are joined by respective webs 4a extending across the head, each pair of legs supporting a respective. pin boss 5.

Extending from one side of each pin boss 5 is a supporting web 6, said webs 6 joining the piston skirt L'said skirt being separated from the side wall 2 of the head by a.transve1se slot 8 and from the pin bosses by respective slots 9 on the pin boss sides of the piston which extend from respective ends of the slot 8, beneath and around the pin bosses, to the arcuate slot 8a, as shown in Figs. 1 and 3, said slots 8 and flabeing formed in the lowermost packing ring groove 3d.

The transverse slots 81; on each pin boss side of the piston extend but a-short distance from a respective leg I of each pin boss, the terminating of said slots 8a leaving a portion ID on the power thrust side I I of the skirt 1 which is integrally connected with the skirt.

Diametrically opposed from the power thrust 5 side ll of the skirt and formed in the-skirt is a longitudinal slot l2 which extends from the open end l3 of the piston to the transverse slot 8, said slot I! being on the compression thrust side ll of the piston and forming adjacent disconnected 10 portions i5. Formed integral with each portion I5 of the skirt is a supporting web l6, said webs. extending across the interior of the skirt to the power thrust side ll of the skirt, each of said webs having an' intermediately disposed elon-'15 gated opening I |,said openings ll being in alinement with the pin bosses 5. Each of the sup.- 1 portingwebs l6 are reinforced by upper and lower disposed ribs It.

The supporting webs I6 parallel the supporting 2o webs 6 of the pin bosses 5 and formed on the inner face of each supporting web I6 adjacent the compression thrust side ll of the skirt is a lug l8- and passing through said lugs I 9 and said webs I8 is a bolt 20 having a fixed head and an ad- 25 justable nut, as shown more clearly in Fig. 4. and. mounted over said bolt 20 and the lugs I9, is a heat treated coil spring 2!, the lugs l9 forming seats for the ends of said spring.

From the above description it is seen that the 3 skirt 1 is separated from the head except through the integral portion 10 on the power thrust side ll of the skirt, reinforcement however being given to the skirt by the supporting webs 6 extending from each pin boss}: to the skirt and a8 35 said pin bosses are depended from the side wall 2 of the head, ample reinforcement for the support of the skirt from the head is provided. In addition, the supporting webs l6 extending from the compression thrust side I 4 of the skirt will 40 reinforce andsupport said thrust side which is weakened for flexibility by the longitudinal slot [2, the supporting webs l6 also being supported by a piston wrist pin; when the wrist pin is mounted in the openings ll of the webs l 6 and the 45 combustion motor, as expansion of the piston and the cylinder in which it is reciprocating occurs,'

compensation of the piston skirtwith respect to the expansion will be taken care of by the slot l2 permitting expansion relief and the spring 2| will automatically permit any moving toward each other of the supporting webs l6 as they fulcrum at 22 on the opposite side of the piston. In the event of contracting forces occurring, the spring 2| will be active on the web J6 for yieldingly forcing them outwardly, thus causing the skirt 1 to fittingly engage the cylinder wall, thus eliminating piston-slap by reason of there being no excess clearance between the skirt and cylinder wall.

The bolt 20 is mainly for the purpose of serving as a retainer for thc spring 2| in the remote event of breakage of the spring, so that broken parts, if any, will be retained and held by the bolt and not permitted to fall into the crankcase of the motor. Springs of this character are heat tested to temperatures much higher than they are subjected in the use of a piston of this character.

Obviously constructional modifications of the device are possible without departing from the spirit of the present invention and therefore it is to be understood that it is not necessary to limit the invention by the terms used in the-foregoing description, excepting such as the state of the art may require.

A piston of this improved character can be made of metal other than aluminum alloy such as Dow metal which is a chemically treated magnesium alloy having'practically no resiliency or spring as does aluminum alloy metal, Dow" metal however being approximately one-third lighter in weight and has approximately onethird more radiant activity than aluminum alloy. The light weight and more radiant activity of 'Dow metal, would permit its use in pistons,

if it were not for the metal being non-resilient, but with the improvements of this invention, Dow metal can be ideally used. In this connection and in the event the piston is made'of Dow metal, the spring 2i will provide the resiliency and hold the skirt 7 in resiliently'yieldable engagement with the cylinder wall.

What I claim is:-

1. A piston comprising a head having pin bosses depending therefrom and a skirt having both a power and a compression thrust side, saidskirt being separated from the pin bosses and from the head except on its power thrust side, said skirt having a single longitudinal split extending from top to bottom on its compression thrust side and having a pair of supporting webs ex.- tending from the power thrust side to said compression thrust side, said webs being free from engagement with said pin bosses, a resilient yieldable member interposed between said webs adjacent said split, an adjustable element mounted through said resilient member and having end engagement with said webs, and a web extending from one side of each pin boss to said power thrust side of said skirt, being the aforesaid'sole connection of the pin bosses with the skirt.

2. A piston comprising a head having pin bosses depending therefrom and a skirt having both a power and a compression'thrust side. said skirt being separated from the pin bosses and from the head except on its power thrust side, said skirt having a single longitudinal split extending from top to bottom on its compression thrust side and having a pair of supporting webs extending from the power thrust side to said compression thrust side, said webs being free from engagement with said pin bosses, and a web extending from one side of each pin boss to said power thrust side of said skirt being ,the aforesaid sole connection of the pin bosses with the skirt.

3. A piston comprising a head having pin bosses depending therefrom and a skirt having both a power and a compression thrust side, said skirt being separated from the pin bosses and fromthe head except on its power thrust side, said skirt having a single longitudinal split extending from top to bottom on its compression thrust side and having a pair of supporting webs extending from the power thrust side to said compression thrust side, said webs being free from engagement with said pin bosses, a web extending from one side of each pin boss to said power thrust side of said skirt being the aforesaid sole connection of the pin bosses with the skirt, and a resilient yieldable member interposed between said first named webs adjacent said split.

4. A piston for an internal combustion motor comprising a head having depending pin bosses formed integral therewith, a skirt having opposing thrust sides and being integrally joined to the head on one of its thrust sides only, the other thrust side of the skirt being carried from the first named thrust side of the skirt by circumferential continuations of the same, a longitudinal slot in the second named thrust side of the skirt extending from top to bottom, a. pair of webs extending from one thrust side of the skirt to the other thrust side and being disposed between the pin bosses and unattached therewith, and a web extending from one sideonly of each pin boss to said power thrust side of the skirt, said last named webs being the sole connection of the pin bosses with the skirt.

5. A piston for an internal combustion motor comprising a head having depending pin bosses formed integral therewith, a skirt having opposing thrust sides and being integrally joined to the head on one of its thrust sides only, the other hrust side of the skirt being carried from the first named thrust side of the skirt by circumferential continuations of the same, a web joining one side only of each pin boss to the first named skirt thrust side, said webs being the only joining means of the pin bosses with the skirt, a longitudinal slot in the second named thrust side of the'skirt extending from top to bottom, a pair of webs' extending from one thrust side of the skirt to the other thrust side and being disposed between the pin bosses and unattached therewith, and a resiliently yieldable member interposed between said second named webs, adjacent and across the longitudinal slot of said slotted skirt thrust side.

ELIVLER C. LONG. 

